I thought I'd share my tube rolling experience with the Ear+ HD (made in Aug 2012) for any users who may want such information in the future. I'm new to tubes so my descriptions may sound a little different than those of others.
I'll start out with the power tube section, the two 12B4As, as there seems to be less discussion on these than on the input tube. After finding my perfect input tube, a Sylvania Gold Brand TMBP 5751 (mine is actually JHS-labelled) I tried three different power tubes. All three pairs are matched. First is RCA made in 1960s. Next is GE/JAN made in 1966. Finally there is Sylvania/JAN made in 1974. It is true that the diference in sound when changing power tubes is much less than when changing the input tube, but I still heard some differences. I'll list each pair and describe the sound as positives and negatives. Remember that a positive for me may be a negative for you, and vice versa.
RCA 12B4A (1960s)
+ Lively and very fast, great warmth and lack of brightness
- Soundstage may be just slightly less holographic than either GE or Sylvania
GE 12B4A (JAN 1966)
+ Lively, good soundstage
- Bass a bit loose (slightly slower-sounding overall), mids less warm and more bright than RCA
Sylvania 12B4A (JAN 1974)
+ Lively and fairly fast, good linearity in the highs, good soundstage
- Mids slightly less warm and more bright than RCA; more similar to GE
Synopsis: The GE and Sylvania tubes sounded quite similar; I'd say the GE is a bit smoother and also a touch brighter. The RCA stood out for being the quickest of the bunch, as the well as the warmest and least bright. If you highly value quickness, go for the RCA. If you listen to a lot of rock and metal and love the texture and crunch of electric guitars, go with the RCA. If you are a holographic soundstage freak, go with the GE or Sylvania. If you are looking for a nice smooth sound, go with Sylvania, or for an ever slightly smoother sound, the GE.
I'll do the same for my experience with input tubes. Changing these out made more of a difference to the sound than swapping power tubes.
Genalex Gold Lion 12AX7 (new production)
+ great high end extension
- thin sounding mids, not a good value for the price (though fairly good sounding overall)
Tung-Sol 12AX7 (new production)
+ mids warm, lush and fairly lively, great value for the money
- somewhat loose bass, soundstage ok but not great, a little slow-sounding
GE TMBP 5751 (NOS)
+ very good overall, good soundstage
- mids less warm and slightly lush, imaging slightly soft, slightly mellow-sounding (perhaps my tube is sub-par?)
GE 5-star GP 5751 (NOS)
+ pretty tight bass, soundstage quite good, sharp imaging, somewhat SS-sounding
- mids slightly less lively and also missing a bit of lushness
Sylvania TMBP 5751 (Gold Brand or equivalent) (NOS)
+ great soundstage, tight bass, lively and fairly lush mids, quick-sounding
- none
Sylvania TMGP 5751 (Gold Brand or equivalent) (NOS)
+ good soundstage, lively mids
- bass slightly loose (a little slow-sounding overall), mids a little too lush
Sylvania/JAN DMGP 5751 (NOS)
+ tight bass, lively mids, good soundstage, tight & quick like SS, good high-end extension
- wish mids were somewhat more lush
Synopsis: Eh, this is so subjective that I don't dare try to say what is best for a given situation. I'm definitely a Sylvania b!tch what it comes to input tubes. I'll probably try a few more tubes in the future - maybe a Bugle Boy and a Raytheon, but I doubt I will find anything I like better than the Sylvania GB TMBP 5751.
Hope this helps anyone out there in the future.